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| // Licensed to the Apache Software Foundation (ASF) under one | |
| // or more contributor license agreements. See the NOTICE file | |
| // distributed with this work for additional information | |
| // regarding copyright ownership. The ASF licenses this file | |
| // to you under the Apache License, Version 2.0 (the | |
| // "License"); you may not use this file except in compliance | |
| // with the License. You may obtain a copy of the License at | |
| // | |
| // http://www.apache.org/licenses/LICENSE-2.0 | |
| // | |
| // Unless required by applicable law or agreed to in writing, | |
| // software distributed under the License is distributed on an | |
| // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY | |
| // KIND, either express or implied. See the License for the | |
| // specific language governing permissions and limitations | |
| // under the License. | |
| import { DataType } from '../type.js'; | |
| import { valueToString } from '../util/pretty.js'; | |
| import { BigIntAvailable } from '../util/compat.js'; | |
| /** | |
| * Dynamically compile the null values into an `isValid()` function whose | |
| * implementation is a switch statement. Microbenchmarks in v8 indicate | |
| * this approach is 25% faster than using an ES6 Map. | |
| * | |
| * @example | |
| * console.log(createIsValidFunction([null, 'N/A', NaN])); | |
| * `function (x) { | |
| * if (x !== x) return false; | |
| * switch (x) { | |
| * case null: | |
| * case "N/A": | |
| * return false; | |
| * } | |
| * return true; | |
| * }` | |
| * | |
| * @ignore | |
| * @param nullValues | |
| */ | |
| export function createIsValidFunction<T extends DataType = any, TNull = any>(nullValues?: ReadonlyArray<TNull>) { | |
| if (!nullValues || nullValues.length <= 0) { | |
| // @ts-ignore | |
| return function isValid(value: any) { return true; }; | |
| } | |
| let fnBody = ''; | |
| const noNaNs = nullValues.filter((x) => x === x); | |
| if (noNaNs.length > 0) { | |
| fnBody = ` | |
| switch (x) {${noNaNs.map((x) => ` | |
| case ${valueToCase(x)}:`).join('')} | |
| return false; | |
| }`; | |
| } | |
| // NaN doesn't equal anything including itself, so it doesn't work as a | |
| // switch case. Instead we must explicitly check for NaN before the switch. | |
| if (nullValues.length !== noNaNs.length) { | |
| fnBody = `if (x !== x) return false;\n${fnBody}`; | |
| } | |
| return new Function(`x`, `${fnBody}\nreturn true;`) as (value: T['TValue'] | TNull) => boolean; | |
| } | |
| /** @ignore */ | |
| function valueToCase(x: any) { | |
| if (typeof x !== 'bigint') { | |
| return valueToString(x); | |
| } else if (BigIntAvailable) { | |
| return `${valueToString(x)}n`; | |
| } | |
| return `"${valueToString(x)}"`; | |
| } | |